Many processes have been disclosed in which transition metal catalyst are used to carbonylate olefins. In particular, palladium-catalyzed carboalkoxylation reactions have been studied for many years as a means of converting butadiene to adipic acid precursors. U.S. Pat. No. 5,026,901 to D'Amore discloses a process for the preparation of linear alkyl pentenoates by reacting butadiene, carbon monoxide, and an alkyl alcohol in an organic solvent with a palladium catalyst.
Palladium catalysts have been recovered from carboalkoxylation of dienes by the addition of onium salt: see U.S. Pat Nos. 4,454,333 and 4,522,760.